The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
An evaporative (EVAP) emissions control system recovers fuel vapor from a fuel tank of a vehicle. The EVAP system includes a canister and a purge valve. The fuel vapor is returned to an intake manifold for combustion in the engine. The fuel vapor displaces oxygen in the intake air when the purge valve is opened. Without adjustment for the fuel vapor, the intake air supplied to the cylinders will be rich. Therefore, the amount of fuel supplied by the fuel injectors should be reduced.